... would have access to the file, and then the creator would be able to get the file and accept the finishing of the task if he deems it satisfactory. This is the feature that I would like the most, and believe will be really useful.
The main feature request aside, here is something else I would appreciate:
Quizzes! It would be really awesome if I could quiz one of my employees with something to make sure that they are well suited for an upcoming task, or if they've been doing their work ;) This ...